1. Field of the Invention
The present invention relates generally to an apparatus for supplying air to an enclosed space and in particular to an apparatus using a nozzle to supply air to an enclosed space. Still more particularly, the present invention relates to an air supply apparatus that supplies filtered air to a passenger cabin through a nozzle.
2. Description of the Related Art
Cabin air systems for aircraft are designed to provide a safe and comfortable cabin environment at different cruising altitudes. At high altitudes, the passenger cabin is pressurized to enable passengers and crew to breathe normally. Further, in providing air in a pressurized cabin system, outside air is mixed with inside air from the passenger cabin and circulated back into the cabin through the cabin air system. The air is distributed into the passenger cabin through overhead nozzles or outlets. Inside the passenger cabin, the air flows in a circular pattern and exits through floor grills on either side of the cabin or through overhead intakes. Typically, about half of the air exiting the cabin is immediately exhausted from the airplane through an outflow valve. The other half of the air is drawn by fans under the cabin floors, mixed with outside air, and then re-circulated into the passenger cabin. The cabin air system also employs high efficiency filters used to trap contaminants, such as bacteria and viruses.
The potential problem of airborne disease in the passenger cabin is, in part, negated by the dilution ventilation provided by the cabin air system. Further, the use of filters to remove contaminants also reduces the risk of airborne infection because the flow of pathogen-free air to the cabin is increased.
Cabin air systems, however, have a limited capacity in filtering and distributing air. Power use and space limitations are present in an aircraft. As a result, the size and number of both fans and ducts cannot be readily increased. One way used to increase air quality is to reduce the passenger count. By reducing the passenger count, the ventilation flow per person is increased. Reducing passenger count is not a popular solution for many business models because the cost increases on a per passenger basis when the passenger count is reduced. Further, fuel is wasted and flight delays occur through increased traffic needed to move the same number of passengers to different destinations. Therefore, it would be advantageous to have an improved method and apparatus for distributing air into a passenger cabin.